Efficacy of transversus abdominis plane block for postoperative pain in in living donor hepatectomy

Introduction : Living liver donors are completely healthy volunteers who do not undergo surgery necessarily due to any health problems. Therefore, providing preoperative well-being in postoperative period at maximum level is very important. These patients are low tolerant individuals for postoperative pain and expect rapid recovery after anesthesia and surgery. Postoperative pain is cause of significant morbidity in liver donors. In recent years, interest in Transversus Abdominis Plane (TAP) block application was increased for postoperative analgesia and to reduce consumption and side effects of postoperative opioid in surgical procedures such as laparoscopic (colorectal, appendectomy, nephrectomy, cholecystectomy) and open abdominal surgeries, total abdominal hysterectomy, open appendectomy and ceserean. Ultrasonography (USG) guidance has shown to shorten duration of TAP block procedure, reduce number of injections, accelerate block starting time and prevent iatrogenic gastrointestinal organ injury. This study was planned to evaluate effect of USG guided TAP block for postoperative analgesia and morphine consumption in liver donors. Material and Methods After obtaining approval of the local ethics committee of medicine faculty of university of Inonu and written informed consent of patient, we included 50 living liver donors of scheduled for right hepatectomy, between age of 18-65 and ASA physical status I-II to study. Patients were randomly allocated into 2 groups; group 1 to undergo ultrasound guided TAP block after general anesthesia; group 2 to undergo general anesthesia but not perform TAP block. Premedication was not performed. Electrocardiograph, noninvasive blood pressure cuff, pulse oximetry, and bispectral index (BIS) were attached to the patients after arriving in the operating room. Induction of general anesthesia was performed by injecting remifentanil 1mg/kg, propofol 2-3 mg/kg and rocuronium 0.6 mg/kg. General anesthesia maintained with 1 MAC sevoflurane in oxygen/air (FiO2%40) and remifentanil infusion 0.25-0.5 µg/kg/dk. Bilateral TAP block was performed with in plane technique under ultrasound guidance with a linear probe at the end of surgery. After needle insertion and negative aspiration, 40 mL mixture of saline and 1.5 mg/kg bupivacaine %0.5 were prepared and administered 20 mL each side. Postoperative analgesia was maintained using PCA with morphine. Patients pain severity in movement and rest, sedation scores, nausea and vomitting, additional demand for analgesic and antiemetics were evaluated in after extubation, postoperative 2, 4, 6, 12 and 24 hours. Results There was no statistically significant difference between the groups in terms of demographic data. There wasstatistically significant difference between the groups in resting VAS scores at 0,2,4,6,24 hours (p<0,05). There wasstatistically significant difference between the groups in movement VAS scores at 0,2,4,6,24 hours (p<0,05). There wasstatistically significant difference between the groups in morphine consumption at 2, 6 and 24 hours (p<0,05). Conclusion USG guided TAP block reduces postoperative morphine consumption and contribute to analgesia at postoperative 24 hours in living liver donor patients with upper abdominal wall incision. Keywords: Living donor hepatectomy, TAP block , patient controlled analgesia, bupivacain, postoperative pain, USG.